Convert unsigned int to signed int C

Question

I am trying to convert 65529 from an unsigned int to a signed int. I tried doing a cast like this:

unsigned int x = 65         


        

Answer 1

To understand why, you need to know that the CPU represents signed numbers using the two's complement (maybe not all, but many).

    byte n = 1; //0000 0001 =  1
    n = ~n + 1; //1111 1110 + 0000 0001 = 1111 1111 = -1

And also, that the type int and unsigned int can be of different sized depending on your CPU. When doing specific stuff like this:

   #include 
   int8_t ibyte;
   uint8_t ubyte;
   int16_t iword;
   //......